Omnivser/IsaacSim Codeful USD Schema Extension

How can I create a codeful USD schema extension. There are examples here, but these seem to use CMake rather than premake, and I’ve had trouble getting that repo to build (see issue I submitted here. The IsaacSim repo has a codless schema, but it appears to me that the code actually has been generated with usdGenSchema separately, I’d like this to be run during the build process.